Many disposable eating utensils such as forks, knives, and spoons are molded from synthetic plastic material. A pair of mold plates have opposing surfaces containing cavities to form a plurality of identical utensils. The cavities are interconnected via channels which are used to supply heated synthetic plastic to the cavities. After the plastic cools and sets, the molded utensils are ejected. The utensils remain interconnected by excess plastic (i.e. runners) from the channels. Depending on the configuration of the mold, any number of utensils are simultaneously molded to form a group of interconnected utensils. The groups of utensils are referred to as racks. The present invention relates to a robotic loading cell for severing the utensils from the molded groups of utensils and packaging the utensils in bags without human intervention.
Automated loading devices are well known in the patented prior art. The U.S. Patent to Belanger et al. U.S. Pat. No. 5,634,547, for example, discloses an apparatus for handling irregularly shaped items such as plastic cutlery wherein the items are removed from a hopper, aligned and separated, and delivered to a conveyor.
While such devices operate satisfactorily, they are not suitable for receiving items from a mold which are joined together. That is, a separate device is required to sever individual utensils from a group of simultaneously molded utensils.
The present invention was developed in order to overcome this and other drawbacks of prior utensil packaging devices by providing a device which both severs a plurality of utensils from molded groups of utensils and transfers the severed utensils to a packaging device. Successive severing and transferring of the utensils greatly increases the speed and capacity of the loading device.
Accordingly, it is a primary object of the invention to provide an apparatus for loading molded plastic utensils including a first conveyor which supplies groups of molded utensils in stacked relation from a mold. Each group includes a planar array of identical utensils which are interconnected via a runner. A gripper device is operable to grip a plurality of aligned and stacked individual utensils and remove them from their respective groups. A robotic transfer mechanism is connected with the gripper device to transfer the stacked individual utensils to a packaging assembly. The transfer mechanism then returns the gripper device to the stacked groups of molded utensils for gripping the next stack of individual utensils. This process is repeated until all of the utensils of the stacked group have been severed and transferred to the packaging assembly. The first conveyor is then driven to supply another plurality of stacked groups of utensils to the gripper device.
According to a more specific object of the invention, the gripper device includes two pairs of elongated parallel fingers which are laterally displaceable between a gripping position where the fingers are moved toward each other to grip a stack of utensils therebetween and a release position where the fingers are moved away from each other to release the utensils. When the fingers are in the gripping position with a stack of utensils gripped therebetween, the gripper is rotated about an axis to break the utensils away from the corresponding runners.
According to yet another object of the invention, the first conveyor includes a clamping mechanism for clamping the runners of a stacked group of utensils while the gripper device is rotated. In addition, the first conveyor includes an ejection mechanism for removing the runners therefrom after all of the utensils have been separated and transferred.
It is yet another object of the invention to provide a controller connected with the first conveyor, the gripper device and the robotic transfer mechanism in order to synchronize the operation thereof for successive and continuous transfer of a plurality of utensils from a mold machine to a packaging assembly.
According to a further object of the invention, a second conveyor is arranged beneath the ejection mechanism to transport the ejected runners to a recycling station.